This invention relates to a process for continuously gasifying coal under superatmospheric pressure and at elevated temperatures by a treatment with oxygen and water vapor and, if desired, additional gasifying agents in a reactor which comprises a rotatable feeder for continuously feeding coal and at least one stirrer arm which revolves in the upper portion of the coal bed, and to a reactor for carrying out the process. Oxygen is often fed as an oxidizing gasifying agent into the gasification process in the form of air and sometimes in the form of pure oxygen or oxygen-enriched air. Water vapor is the most usual form of the reducing gasifying agent which is also required.
Gas-producing reactors are known which comprise a water-cooled pressure housing. A feed lock and means for distributing the coal to be gasified are provided in the upper portion of the reactor. The gas producer is provided at its lower end with a rotatable grate for feeding and distributing the gasifying agents and for discharging the ash which has been formed. The ash is withdrawn below the rotary grate through an ash lock. In such reactor, gasification is effected at temperatures up to and above 800.degree.C. and under a pressure up to about 50 kilograms above atmospheric pressure. A known gas producer is shown, e.g., in the U.S. Pat. No. 2,667,409.
The German Pat. No. 1,021,116 describes a gas producer which comprises stirrer arms revolving in the coal bed. These means disintegrate coal which has caked and are assisted by additional scraping fingers. Particularly with coal having a high caking capacity, these measures cannot always avoid a formation of large lumps of coal. If in such cases the gas producer is required to operate at a high throughput rate, a non-uniform gasification of the feedstock may give rise to disturbances which adversely affect the productivity of the process.